Go on a virtual stroll through century-old London, with this new interactive map produced by Expedia. Named “Historic London,” the app takes you through 14 notable sites throughout the British capital, from Buckingham Palace to a view of St. Paul’s Cathedral from Fleet Street. Archival images of the sites from the late 1800s and early 1900s are overlayed onto the streetview of today, so you can easily compare what has and hasn’t changed over the last 100 years.

Buenos Aires' contemporary urban landscape as we know it today provides a tempered mix of historical and recent construction projects. As one of the most beautiful cities in South America, it's wide boulevards and grand buildings, based on European models, have morphed to embrace the needs of a modern metropolis.